The present invention relates to a process for the production of shaped articles of high density graphite having excellent moldreleasing property which comprises incorporating amorphous carbon powder or artificial graphite powder with several percents by weight of boric acid or boron oxide as a sintering-promoting agent and baking the mixture under a pressure of several hundred kg/cm.sup.2 without the aid of any binding agent such as pitch.
At the present time, the production of shaped articles of high density graphite is an important research objective and is attacked by a variety of processes. Attempted hitherto are a process wherein a device is used for carbonaceous materials or binding agents such as pitch to be incorporated thereinto to increase the carbonization rate and contraction by graphitization is promoted to obtain high density products, a process wherein a carbonaceous material is sintered under pressure to increase the carbonization rate of a binding agent and contraction of the material is effected on sintering to obtain high density products, a process wherein a sintered material is impregnated with a liquid hydrocarbon and then the impregnated material is sintered to clog pores of the material for obtaining high density products, a process wherein a sintered material is permeated with a gaseous hydrocarbon and then the permeated material is heated to effect pyrolysis of the gaseous hydrocarbon in the internal pores of the material for clogging the pores, and a process wherein a sintered material is graphitized under mechanical pressure to effect collapse of pores in the material by creeping. In these processes, the products are produced from a starting material containing a binder. A process wherein a carbonaceous material is sintered under ultrasuperatmospheric pressure is also attempted as a process using no binder.
However, these prior art processes using a binder require complicated and/or costly operations. It is considerably difficult to produce products having a bulk density of at least 1.9 following to these processes and, when possible at all, the products will be expensive.
On the other hand, the process wherein sintering of a carbonaceous material is effected under ultra-superatomospheric pressure in the absence of a binder requires an extremely high pressure of about several ten thousand atoms and is unable to produce large-sized products on account of the limited capacity of the pressure apparatus. Thus, there is a great demand for developing a process for producing shaped articles of high density graphite in a simple manner.